lib/smtp: add function Params to Extension interface

The Params will return the list of argument that supported by extension.

3 files changed, 13 insertions, 0 deletions

diff --git a/lib/smtp/extension.go b/lib/smtp/extension.go
index 016d473e..6adcecc0 100644
--- a/lib/smtp/extension.go
+++ b/lib/smtp/extension.go
@@ -14,6 +14,11 @@ type Extension interface {
 	Name() string
 
 	//
+	// Params return the SMTP extension parameters.
+	//
+	Params() string
+
+	//
 	// ValidateCommand validate the command parameters, if the extension
 	// provide custom parameters.
 	//
diff --git a/lib/smtp/extension_dsn.go b/lib/smtp/extension_dsn.go
index b59429df..0de388cb 100644
--- a/lib/smtp/extension_dsn.go
+++ b/lib/smtp/extension_dsn.go
@@ -15,6 +15,13 @@ func (dsn *extDSN) Name() string {
 }
 
 //
+// Params return the SMTP extension parameters.
+//
+func (dns *extDSN) Params() string {
+	return ""
+}
+
+//
 // ValidateCommand validate command parameter for MAIL and RCPT.
 //
 func (dsn *extDSN) ValidateCommand(cmd *Command) (err error) {
diff --git a/lib/smtp/server.go b/lib/smtp/server.go
index de226737..51080c7f 100644
--- a/lib/smtp/server.go
+++ b/lib/smtp/server.go
@@ -214,6 +214,7 @@ func (srv *Server) handleCommand(recv *receiver, cmd *Command) (err error) {
 		body := make([]string, len(srv.Exts))
 		for x, ext := range srv.Exts {
 			body[x] = ext.Name()
+			body[x] += " " + ext.Params()
 		}
 
 		if !recv.isAuthenticated {